388 VITAL STATISTICS. 



TO SHOW THE ACTION OF CILIA. 



Kill a frog, and destroy the brain and spinal cord as directed on p. 37. 

 Lay the frog on its back ; divide the lower jaw longitudinally, and con- 

 tinue the cut as far as the stomach. Pin the flaps out to the sides, thus 

 laying bare the roof of the mouth and gullet. If the lining of the mouth 

 seems dry, moisten it with "saline solution." Cut some cork fine, like 

 sawdust, and drop a little of it on the roof of the mouth between the 

 eyes. The current of mucus, caused by the vibration of the cilia, carries 

 the particles toward the stomach. Snip off a little of this ciliated lining 

 and mount in saline solution, and examine under a high power of a 

 good microscope. Or snip off a little of the margin, or scrape a little 

 off the surface of the gill of a clam, and examine as above. 



